Method of making aldehydes and separating the same from the other products formed



A. A. BACKHAUS ANS) F. B. ARENTZ. METHOD OF MAKING ALDEHYDES AND swmmmu THE SAME Pzztcnted Dev. 13, 1921.

%1 c3 Hoawuug 30 4 THE OTHER PRODUCTS FORMEDa UNITED STATES PATENT OFFICE.

Anrrron a BAGKHAUS, or BALTIMORE, m) rnnns. AREN'TZ, or scans BAY, MARYLAND, ASSIGNORS TO U. .s. INDUSTRIAL ALCOHOL 00., A CORPORATION OF WEST VIRGINIA.

METHon or MAKING ALnEHYnrs AND SEPARA'I'ING THE SAME FROM THE OTHER.

PRODUCTS roBMEn. I

To all whom it may concern Be it known that we, ARTHUR A. BACK- H AUs, of Baltimore, in the State of Maryland, and FRED B. ARESTZ, of Curtis Bay, in the county of Anne Arundel. and in the State of Maryland, have invented a certain new and useful Improvement in Methods of ment in many different forms, for the pur- Making Aldehydes and Separating the Same from the other Products Formed, and do hereby declare that thefollowing is a full, clear, and exact description thereof.

Our invention relates particularly' to a process of producing. aldehydes, but it has referenceparticularly to the production of acetaldehyde.

object of our invention is to provide .Ja process by means of which'aldehydes, and

particularly acetaldehyde, may be readily formed from the correspondingalcohol.

A further object is to carry out said process by means of a catalyzer.

The object of our invention is especially to recover the aldehyde and separate it from the other products of the process in an advantageous manner.

Further objects of our invention including the production of acetic acid will appear from the detailed description thereof contained hereinafter.

While our invention is capable of embodipose of illustration we shall describe only one form of our process hereinafter, and while said process is capable of being carried out with many different types of apparatus, for the purpose of illustration we have shown only one type of apparatus for use in connection therewith in the accompanying drawing, in which The figure is a diagrammatic representation partly in section, of an apparatus which may be used in carrying out our invention.

In the drawing, we have shown an alcohol still 1, adapted to be heated by means of a steam jacket 2, having a vapor outlet pipe 3, which passes through a preheater, 4, adapted to be heated in any suitable way, as for example by an oil jacket 4, having inlet and outlet pipes 4 and 4.' Thetube 3 is connected to a catalyzer 5, which is comprised of a copper tube 6, carrying a quantity of granular porous material 6, such for p cated at the top of the tower.

Specification of Letters Patent. Patentd De 13 1921 Application filed June 15, 1918. Serial 1%. 240325.

example as pumice stone, unglazed porcelain, charcoal or terra cotta, carrying throughout the same particles of a finely divided catalyzer metal such for example as copper, nickel, chromium or iron, which may be deposited therein by any suitable means, but preferably in such a manner as to involve the reduction of an oxid of the metal by a current of hydrogen, as for example in accordance with the process of making catalyzers set forth in application, Serial Kurd ber 240221, filed June 15, 1918. by Arthur A. Backhafus. I

Sa1d catalyzer 5 is provided with any suitable heating means, but may. for example. be provide for this pu'rpose with a heat 1ng acket 7, having inlet and outlet pipes 8 and 9, respectively, for supplying a curtain a compressor 16%, and thenceto a scrubbing tower or column 17.

The vapors in the tower 1'7 pass through a series of liquid sealed pans 18, constructed in the same manner in which scrubbing towers or columns are ordinarily made, in which pans a current of absorbing liquid iscaused to flow in the opposite direction from an inlet pipe 19 lo- The absorbmg liquid may be water or alcohol, but said liquid is preferably comprised of acetic acid, the most preferred form of which for this purpose is glacial acetic acid, in which the aldehyde formed is very soluble. In this way an acetic acid containing 50% of acetaldehyde may be obtained and will how out of the tower 17 by means of an 'outlet pipe 20, and thence into a receiver 21, from which it may be drawn off by an outlet pipe 22. The hydrogen passes'out of the tower 17 by means of a pipe 23, and may be collected in an suitable manner.

carrying out our process, a quantity of .pipe 20, and which comprises approximately an alcohol, such for example as ethyl alco,

temperature of between 250 and 350 (1., but preferably of approximately 300 C., be-

fore they enter the catalyze'r 5, the temperature atwhich it is desired to act upon the alcohol vapors with the .catalyzer. The alcohol vapors, therefore, enter the catalyzer 5 at the required temperature, so that the formation of acetaldehyde immediately begins as soon as the vapors reach the finely divided metal carried upon the granular particles Within the catalyzer tube 6. The oil jacket 7 maintains the vapors in the tube 6 at from 250 to 350 (1., but preferably about 300 C., throughout the entire length of said tube, and a large percentage of the alcohol vapors is thus decomposed to form acetaldehyde and hydrogen.

The vapors passing out of the catalyzer by means of the tube'10 are conducted through the condenser 11, maintained "at a tempera- .ture of 2030 (l, where. any alcohol vapors present are condensed, and,,are collected in the receiver 14, from which the alcohol may be drawn off by means of the-pipe 15. The acetaldehyde and the hydrogen pass out of the receiver 14, and are conducted to the scrubbing tower or column 17, where the ascending vapors of acetaldehyde and hydrogenare subjected to a counter current of an absorbing liquid, such as water, alcohol or acetic acid, preferably glacial acetic acid, by passing through the series of liquid sealed pans 18 therein, until substantially all of the acetaldehyde has become absorbed in the acetic 301d. and forms a solution, which passes out-of the tower 17 by means of the one part ofglacial acetic, acid and one part of acetaldehyde.

The hydrogen passes away from the top of the'tower 17 by means of the pipe 23, from which the hydrogen may be collected 1n any suitable manner.

n this process it is preferable to use acetic acld as the absorbing medium, particularly cwhen the acetaldehyde recovered is to be a changed into acetic acid, as for example by the action of a'current of air under pressure of 50-75 lbs. and at an elevated temperature of 4565 o. c

While We have described our invention above'in detail, We wish it to be understood that many changes may be made therein without departing from, the spirit of our inventlon.

We claim: f

1. The process comprises vapors of alcohol over a catalytic agent, thus forming acetaldehyde, then separating the resulting aldehyde and hydrogen by passing the vapors through a scrubbing tower containing acetic acid and forming acetic acid from the aldehyde dissolved in the acetic acid by subjecting the solution to heated air under pressure.

2. The process which comprises passing vapors of alcohol over a catalytic agent,- thus forming acetaldehyde, then separating the resulting aldehyde and hydrogen by passing the vapors through a scrubbing tower containing glacial acetic acid and forming acetic acid from .the aldehyde dissolved in the acetic acid by subjecting the solution to heated air under pressure.

3. The process which comprises passing vapors of alcohol over a catalytic agent. thus forming acetaldehyde, then separating the resulting aldehyde and hydrogen by passing the vapors through a scrubbing tower containing acetic acid. the vapors and liquid being passed throughthe tower on the counter-current principle and forming acetic acid from the aldehyde dissolved in the acetic acid by subjecting the solution to heated air under pressure.

4. The process which comprises passing vapors of alcohol over a catalytic agent. thus forming acetaldehyde, then separating the resulting aldehyde and hydrogen by passing the vapors through a scrubbing tower containing glacial acetic acid, the vapors and liquid being passed through the tower on the counter-current principle and forming acetic acid from the aldehyde dissolved in the acetic acid by subjecting the solution to heated'air under pressure.

'5. The process of preparing an acid from an alcohol by Way of aldehyde which comprises (1) a'thermo-catalytic decomposition v of the alcoholwith liberation of hydrogen, (2) a direct absorption of the simultaneously produced aldehyde in the corresponding acid, and (3) anoxidatibn of the aldehyde while in admixture with said acid, to increase the acid content of the mixture.

6. The process of preparing acetic acid from alcohol by Way of acetaldehyde which comprises 1) a thermo-catalytic decomposition of the alcohol with liberation of hydrogen, (2') a direct absorption of the simultaneously produced acetaldehyde in acetic acid, and (3) an oxidation of the acetaldehyde while in solution of the acetic acid.

In testimony that we claim the foregoing we have hereunto set our hands.

ARTHUR A. BACKHAUS. FRED B. ARENTZ.

Witnesses:

J OHN' P. GISGHEL, ARTHUR WRIGHT. 

